JP 10-236753 A discloses a double-decker elevator. The known elevator has two cars which are arranged one above the other in a car frame. The two cars can hereby move relative to each other. For this purpose, hydraulic cylinders are arranged in a counterweight frame. A traction cable which is connected at one end to the counterweight frame and at the other end to the car frame is guided over a drive pulley. Moreover, a second cable in addition to the traction cable is guided over a freewheeling pulley and is connected at one end to the hydraulic cylinders and at the other end to one of the cars. When the hydraulic cylinders actuate the second cable, the cars are moved relative to each other.
The double-decker elevator known from JP 10-236753 A has the disadvantage that it has a complex design. On the one hand, the design of the counterweight frame is complex because the hydraulic cylinders move with the counterweight frame through the elevator shaft, which requires an additional control means. Moreover, a cable guide for the second cable is additionally needed. Elongation or shortening of the traction cable and the second cable, occurring during operation, are hereby also possible, which results in undesired relative movement between the two elevator cars.